ICUMSA News n°74 – October 2014

Message from the President

29th Session of ICUMSA

The 29th session of the International Commission for Uniform Methods of Sugar Analysis (ICUMSA) took place in Ribeirão Preto, Brazil, on 4 and 5 September, 2014. It was the second time that the ICUMSA session has been held in Brazil, following the 2006 meeting in the resort town of Sao Pedro. The world’s largest sugar exhibit took place in Sertazinho, 20 km away in the week prior to the ICUMSA conference.

Forty-five delegates from fifteen different countries attended and special tribute was paid to Professor Klaus-Jürgen Rosenbruch and to Dr. Georg Steinle, who had both passed away since the last ICUMSA session.

After the 28th session, in Cambridge (UK), Scientfic Subjects were reorganised by combining them, reducing the number from 14 to 6. New Subjects for “Indirect Methods and New Technologies” (S7) and “Sampling and Sample Preparation” (S8) were also created. During the two-day session, reports were given for all nine General Subjects and all eight Scientific Subjects.

Three new Official Methods, including:

– Determination of Specified Heavy Metals in White Sugar

– Determination of the Relative Activity of Commercial Amylase as used in Sugar Cane Processing and Refining (elevated from the Tentative Status); and

– Determination of Apparent Sugar Content by Polarisation, Soluble Solids Content by Refractometry and Fibre Content (calculated) in Cane and Bagasse using Wet Disintegration to obtain an Extract, Pressure Filtration and Near Infra-Red Polarimetry”: and

– Determination of Apparent Sugar Content by Polarisation, Soluble Solids Content by Refractometry and Fibre Content (calculated) in Cane using a Press to obtain Cane Juice according to Berding and Pollock, Pressure Filtration and Near Infra-Red Polarimetry.”

Four items were in discussed in detail without any final conclusion (at this stage):

1. Starch in Raw Sugar. In 2012 the SPRI rapid starch Method (GS1-17) was given Official status in the region of 300 to 1000 mg/kg. A proposal was put forward to have the lower limit of 300 mg removed. A working group chaired by GS1 Referee Andrew Harrison considered this but since no new evidence had been brought forward, the proposal was not accepted and the 2012 position remained. A new research method for starch in raw sugar proposed by Gillian Eggleston, was also discussed. The proposal for a comparative study of the important starch methods was not seen as required at this stage.

2.The Referee for S4 Physical Methods, Mathis Kuchjeda, proposed to add a gravimetric method for the preparation of “normal sugar solutions” for the determination of the polarimetric sugar content of pure sugar. He stated in his report “Mass determination by weighing is independent of temperature effects and features a higher precision. In this context it has to be mentioned that the volume calibration of volumetric flasks is carried out by using weight comparators. Statistical errors for the mass determination per weight can be expected to be within the tolerances of the balances. The precision of micro scales (precision class I) is ± 0.0001 g compared to a precision of an ICUMSA 100 mL volumetric flask of only ± 0.02 mL.” The proposal was not accepted before further studies have taken place.

3.Mathis Kuchejda also proposed changes for the calibration of the polarimeters using quartz plates.No agreement could be reached and the proposal was transferred back to the German National Committee to develop further.

4.New evidence in respect to the Method procedure was brought forward in respect to the Microbiological method for Thermophilic Acidophilic Bacteria (TAB) and Guaiacol producing TAB (GP-TAB) in Sugar Products. It could therefore not receive Official status yet and will undergo further re-writing.

New Numbering System for Methods

For some time, the numbering system of ICUMSA Methods had been criticised by some users for its complexity and by other international organisations, such as Codex. After many years of discussions, the Executive decided to give each method a new four-digit number. In order to facilitate the transition, the second digit will indicate the General Subject responsible for the Method (as the first digit in the current system) and the last two digits will be similar to the last one or two digits after the dash in the current system. This means that Method GS1/2/3/9-1 (2011) will become Method 1101. The new numbering system will be introduced in early 2016 and information will soon be available on the ICUMSA website: www.icumsa.org.

In addition to the new numbers, ICUMSA plans to republish all Methods. This was stated by Dr Hanjo Puke. In his presentation, he gave examples showing that the terminology used by ICUMSA is not uniform and not according to the standards published by ISO. The secretary plans to rewrite the Methods during the next few years. ICUMSA Methods are used in many laboratories outside the sugar industry, where difficulties might arise in understanding the specific language of the sugar industry.

Election of officers

Geoff Parkin, who has been president of ICUMSA since 2006, was re-elected for another four-year term by the executive. Hanjo Puke, secretary since 2002, also was reelected until 2018, as well as the treasurer, Clive Shelton.

Founding of ICUMSA Ltd.

In order to better protect it’s intellectual property, and to ensure that the name is protected, ICUMSA now has new status as a “Company Limited by Guarantee” in the UK. This type of company status is designed for non-profit organisations like ICUMSA. The Executive Committee had previously approved the plans during the meeting in 2012.

Next conference

During the Executive Committee meeting it was agreed that the 30th ICUMSA Session will take place in Warsaw, Poland, on 9 and 10 June, 2016.

Subject 7 Report; Amélia de Andrade Ferraz

Once ICUMSA decided to include Indirect Methods of Analysis as a new Subject, it became clear that a method was required for how to approach the validation of such methods, since they can’t be subject to the traditional collaborative study. At the 29th Session, the referee for S7 proposed general guidelines for validating indirect methods of analysis. By using published guidelines for single laboratory validation of methods, the referee developed an approach and tested it using a reflectance method for white sugar colour. The report presented was based on comparison of results from an indirect method and the official ICUMSA method for solution colour. It was conducted in two sugar factories, the Nordic Sugar factory in Nykøbing, Denmark, and the Pfeifer & Langen, Zaharul Oradea SA factory in Oradea, Romania. The results showed the proposed general guidelines work well when applied to the Neltec ColourQ reflectance method for measuring white sugar colour in the range of 20-50 ICUMSA units, consequently the referee proposed that the indirect methods of analysis validated in accordance with the general guidelines proposed, that comply with the requirements for the method performance characteristics, should be given “ICUMSA Accepted Status”.

During the next 2 years further indirect methods of analysis should be tested and the proposed guidelines reviewed in collaboration with the Referee and Associate Referees of S2.

Please contact the Referee of S7 if you wish to test the guidelines proposed on an indirect method of analysis that is already in practical use and that is serving a useful function in your industry and trade, and is not likely to be validated in the future through a collaborative trial.